In vitro bacterial interference in the nasopharynx of otitis media-prone and non-otitis media-prone children

Objective: To compare the frequency of recovery of potential pathogens and aerobic- and anaerobic-interfering bacteria in the nasopharynx of otitis me dia-prone (OMP) with that in non-OMP (N-OMP) children. Patients and Methods: Nasopharyngeal cultures were obtained from 20 OMP and 20 N-OMP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. Results: Eighteen potential pathogens were isolated from 12 of the 20 OMP c hildren, and 9 were recovered from 5 of the 20 N-OMP children (P<.05). Fift y-eight aerobic and anaerobic isolates with interfering capability against 4 potential pathogens were recovered from 5 of the OMP group, and 139 from 17 of the N-OMP group (P<.05). These interfering organisms included alpha-h emolytic streptococci, nonhemolytic streptococci, Prevotella species, and P eptostreptococcus species. Conclusion: The nasopharyngeal flora of N-OMP children contains more aerobi c and anaerobic organisms with interfering capability and less potential pa thogens than that of OMP children.